CAYSTON® Systemic Exposure
CAYSTON has low systemic exposure
- Mean sputum concentrations of aztreonam 10 minutes after dose administration in patients receiving CAYSTON (75 mg) 3 times a day for 28 days are shown below*:
*There was considerable variability observed between patients.
- Mean peak plasma concentrations were reached 1 hour postdose in patients receiving CAYSTON (75 mg) 3 times a day. Values shown below†:
†There was considerable variability observed between patients.
- In contrast, serum concentration following a one-time, 30-min IV administration of aztreonam for injection (500 mg) was approximately 54 mcg/mL
- There was no systemic accumulation of CAYSTON
- Evaluation of plasma and urine aztreonam concentrations in patients following administration of CAYSTON indicated low systemic absorption of aztreonam
- About 10% of the total CAYSTON dose was excreted in the urine as unchanged drug, as compared to 60%-65% following IV administration of aztreonam for injection